Propeller



Feb. 13, 1934.

J. M. WILSON PROPELLER Filed Feb. 1933 Patented Feb. 13. 1934 UNITED STATES PATENT OFFICE 12 Claims.

This invention relates to propellers and more particularly to a hub for an airplane propeller.

Airplane propeller hubs for removable blade propellers, as commonly constructed, are, divided transversely into two parts and each blade attaching device or socket is also divided into two parts, one part of each socket being rigidly secured to or formed integral with the corresponding part of the body portion of. the hub. In order to separate the two parts of the socket for the purpose of inserting or removing the shank of a blade it is necessary to separate the two parts of the body portion of the hub and this releases all the blades. removed from the hub and replaced it is necessary to accurately adjust the blade and the attaching device to secure the proper pitch and balance and this cannot be done satisfactorily without the use oil a balancing machine. If one blade of a propeller is injured, even slightly, it is necessary to ship the propeller as a whole toa factory or flying field which is equipped with a balancing machine and which may be at a considerable distance from the location of the plane having the damaged propeller. Even a two blade propeller assembled can be shipped by airplane only with dimculty and a three blade propeller assembledcannot be shipped on an ordinary airplane and difliculties are encountered in shipping the same by rail or by truck, particularly with the larger size propellers. As a result a great deal of delay and expense is incurred insecuring the necessary repairs or replacements for an injured propeller.

One object ofthe invention is to provide a propeller hub of such a character that each blade and its attaching device or socket may be secured to or detached from the hub without.

disturbing the remaining blade or blades.

.A further object of the invention is to pro vide a propeller hub of such a character that a single blade and its attaching socket may be mounted on a master hub and properly set for pitch and balance on a balancing machine and when this blade unit, consisting of the blade and socket, are attached to the propeller hub the propeller as a wholewill be in perfect balance.

A further object of the invention is to provide such a propeller hub which will be simple in its construction and on which the blades can be quickly and easily attached to the hub and accurately positioned thereon.

Other. objects of the device will appear as the device is described in detail.

In the accompanying drawing Fig. 1 is a sectional view taken through a portion of a propeller hub with the blade partly broken away; Fig. 2 is a transverse section taken on the 1ine 22 of Fig. 1; and Fig. 3' is a transverse section taken poonthelines-sofi'lgil.

When a blade is In this drawing I have illustrated one embodiment of my invention but it will be understood that this has been chosen for the purpose of illu'stration only and that the hub may take various forms without departing from the spirit of the invention.

The hub comprises a body portion 5 and an attaching device or socket 6 adapted to receive,and to be rigidly secured to, the shank of the propeller blade 7. The attaching socket is formed-separately from and is detachably secured to the body portion of the hub. The body portion of the hub may be of any suitable character. It is here shown as an elongated sleeve adapted to receive the propeller shaft and provided with suitable devices for securing the same on the shaft, as shown at 8. The hub may be provided with any suitable number of blade sockets but usually there are two or three of these sockets and they are spaced circumferentially about the hub. Each socket is divided longitudinally into two parts of equal size. The lower portions of the two parts of the socket abut directly one against the other. as shown at 9, while the outer portions thereof are spaced a short distance apart, as shown at 10, to permit the same to be pressed inwardly into engagement with the shank of the blade 7. Preferably a clamping device, such as a hinged collar 11, is placed about the outer end of movement of the blade with relation to the socket.-

In the present construction the blade is also provided at its inner end with a head 15 which is located beyond the inner end of the socket and is of a diameter greater than the diameter of the opening through the inner end of the socket, so that the head of the blade overlaps and engages the inner end of the socket and is thus further held against outward movement. The socket may be rigidly connected with the body portion of the hub in any suitable manner. In the particular construction here illustrated the body portion of the hub is provided with an annular boss 16 which forms within the same a recess 17 and this boss has near its outer end a circumferential flange 18. The outer end of this boss forms a seat for the socket and the inner end of the socket is provided with a circumferential flange 19 opposed to the flange 18 of the boss, this flange 19 being of course formed in two parts which are carried by the respective parts of the socket. Preferably the lower surface of the flange18 and the upper surface of the flange 19 converge outwardly so" as to provide a tapered construction. A suitable clamping device engages the opposed parts of the boss and the socket and rigidly connects the same one to the other. .As here shown, this clamping device is in the form of a hinged collar 20, thetwo parts of which are pivotally connected one to the other at 21 and are provided in their inner faces with grooves 22 to receive the flanges 18 and 19. The walls of the groove diverge outwardly and when the clamping collar is contracted by the bolt 23 the flanges 18 and 19 will be clamped tightly in engagement one with the other and the socket will be rigidly secured to the body portion of the hub with the head 15 of the blade seated in the recess 17. In order to maintain the proper balance of the propeller it is desirable that the pivot point 21 and the bolt 23 to be arranged accurately in the line of rotation of the hub, and in order that the clamping device may be easily located, and maintained in its proper location, the socket and the clamping device are provided with interlocking parts. In the present instance, the clamping device is provided adjacent to the pivot pin with a projection or pin 24 which pro- Jects into a recess 25 in the socket. The socket itself is accurately positioned on the body portion of the hub by providing the two devices with interengaging parts, which may be so arranged that the socket may be placed upon the body portion 0! the hub in one position only. Preferably the boss 16 is provided with one or more recesses 26 adapted to receive dowel pins 2'7 carried by the inner end of the socket. The clamping collar 11 for the socket extends transversely to the line of rotation of the hub and is adjusted circumferentially oi the socket to secure a proper balance, in the usual manner.

It will be apparent therefore that by removing the clamping device 20, which can be done by merely withdrawing the bolt 23, the socket and the propeller blade may be removed from the body portion of the hub and when repaired may be readily reattached to the hub. when the hub is of a standard construction, and the corresponding parts of different hubs are interchangeable a damaged blade and its socket, constituting a blade unit, may be detached and sent to the factory or repair station for repairs. when the blade has been repaired the blade unit may be mounted on a master hub and accurately balanced, the socket being rigidly secured to the blade in proper relation thereto. When this blade unit is reassembled on the propellerhub the propeller as a whole will be imperfect balance, no adjustments of any kind being required, because the blade unit can be mounted on the body portion of the propeller hub in one.position only and this is the position in which it has been set for pitch and balanced on the balancing machine. The use of such a hub not only eliminates the necessity of shipping the propeller as a whole to and from the repair station, when repairs are necessary, but it is obviously pomlble to substitute a new blade unit for the damaged blade and this makes it practical to carry an extra blade unit in the airplane, which unit is available for the purpose of replacing a damaged blade.

While I have shown and described one embodiment of my invention 1 wish it to be understood that I donot desire to be limited to the details thereof as various modliicationsmay occur toa person skilled in the art.

mergers 1. In a propeller, a hub comprising a body portion and a blade socket separate from said body portion, said body portion having an annular boss on which said socket is seated, said socket having an opening through the inner end thereof of a diameter less than the interior diameter of said boss, a blade having at its inner end a head, means for securing said blade in said socket with said head arranged beyond and overlapping the inner end of said socket, and means for detachably securing said socket to said body portion with the blade head seated in said boss.

2. In a propeller, a hub comprising a body portion and a blade socket separate from said body portion, said body portion having an annular boss on which said socket is seated, a blade mounted in said socket and extending beyond the inner end thereof, means tor rigidly securing said blade in adjusted positions in said socket independently of said body portion, and a clamping device engaging adjacent portions of said socket and said boss to secure said socket to said body portion with the inner end of said blade seated within said boss.

3. In a propeller, a hub body, a blade socket separate from said hub body, adapted to be mounted thereon and having means for positively locating said socket in a predetermined position on said hub body, a blade rigidly mounted in said socket, and means for rigidly and detachably securing said socket and said blade as a unit to said 105 hub body in said predetermined position, said blade and socket unit being adjustable to establish pitch and balance, whereby a blade and socket unit which has been adjusted in one propeller may be transferred to anotherpropeller having 1 0 an identical hub body and will be in proper pitch and balance with relation to the last mentioned propeller without further adjustment.

4. In a propeller, a hub body'g'a blade socket separate from said hub body and adapted to be mounted thereon, said socket and said hub body having cooperating parts to positively locate said socket in a predetermined position on said hub body, a blade adjustably mounted in said socket, means for rigidly securing said blade in adjusted position in said socket, said securing means being adjustable to establish balance, and means for rigidly and detachably securing said blade and said socket as a unit to said hub body, whereby a blade and socket unit which has been adjusted for pitch and balance in one propeller may be trans. erred to another propeller having an identical hub body and will be in proper pitch and balance with relation to said propeller.

5. In a propeiler, a hub comprising a body por- 39 tion and a blade socket separate from said body portion, a blade mounted in said socket for adjustment with relation thereto, clamping means for rigidly connecting said blade and said socket in relatively adjustedpositiops independently of said body portion, and means for securing the 145 assembled blade and socket to said body, said socket and said body portion having interlocking parts to accurately locate said socket in a predetermined position with relation to said body ponfor rigidly seeming said 7. In a propeller, a hub comprising a body portion and a blade socket separate from said body portion, said body mrtion having a part forming a seat and said socket having a part to engage said seat, one of said parts having a recess and the other of said parts having a projection to enter said reces'sto positively locate said'socket in a predetermined position on said body portion, a blade mounted in said socket and adjustable with relation thereto, means for securing said bladev in an adjusted position in said socket, and means for detachablysecuring said socket and said blade as a unit to said body portion.

8. In a propeller, a hub comprising a body portion, a blade socket separate from said body portion, a blade adjustably mounted in said socket with its inner end extending beyond the inner end of said socket, said body portion having a recess to receive the inner end of said blade, means for detachably securing said socket in a predetermined position on said body portion, and means for rigidly connecting said blade and said socket in adjusted positions independently of said "body portion and said securing means.

9. In a propeller, a hub comprising a body portion and a blade socket separate from said-body 1 portion, said body-portion having. a projecting part to form a seat for said socket, said socket having means for positively locatingv the same in a predetermined position on said seat, said part of said body portion and said socket having opposed fianges, a clamping device engaging said flanges to rigidly secure said socket to said body portion in saidpredetermined position, a blade mountedv in said socket and adjustable with reintion thereto, and means for securing said blade in said socket in adjusted positions with relation thereto.

10. In a propeller, a hub comprising a body portion and a blade socket separate Irom said body portion, said body portion having a projecthis part to storm a seat for said socket, said socket having means to positively locate the same in a. predetermined position on said seat, saidpart of said body portion and said socket having opposed flanges, a clamping device engaging said flanges to rigidly secure said socket to said body portion in said predetermined position, said clampin device and said socket having interlocking parts to properly locate said clamping device, a blade mounted in said socket and adjustable with relation thereto, and means for securing said blade in adjusted positions in said socket.

11. In a propeller, a hub comprising a body portion and a blade socket separate from said body portion, said socket being divided longitudinally into two parts, means for'clamping the two parts of said socket about the shank of the blade, said socket and said body portion having cooperating parts to positively locate said socket in a predetermined position on said body portion, and an attaching deviceto secure the two parts of said socket rigidly to said body portion in said predetermined position.

12. In a propeller, a hub comprising a body portion and a blade socket separate from said body, means for detachably securing said blade socket in a predetermined position on said body portion, said body portion having an exterior recess,ja blade mounted in said socket and having a head seated in said recess, said socket having a part overlapping the outer side of said head, and no means for rigidly securing said blade in said socket. 4 I

- 1 JOHN MARK WILSON.

comm-one or CORRECTION;

Patent No. 1,947,073.

JOHN MARK'WILSON.

February 13, 1934;

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Page 2, line 53, for

"imperfect" read in perfect; and that the said Letters Patent should be read with this correction theteinthat the same may conform to the record. of tbe'l.

case in the PstentOifice.

Signed and sealcdlthis ZSth-day of September, A. D. 1934.

(Seal) Leslie Frazer Acting Commissioner of Patents. 

